This invention relates to a rail anchorage arrangement that is for fastening a rail. All rails are anchored but the invention is particularly concerned with an anchorage arrangement for rails used by cranes. These rails transfer heavy lateral forces to their anchorages and the anchorages must transfer the heavy lateral forces to a fastening device which is secured to a support structure.
As shown in FIG. 1 of the accompanying drawings, which is a side view, a prior art fastening device is a metal bar 1 screw-threaded at one end and welded at its other end, at 2, to the support structure upon which the rail anchorage is to rest. This allows only a small amount of weld in relation to the cross-sectional area of the screw-threaded part of the bar and limits the material of the bar to being a standard weldable metal.
Reference is also made to U.S. Pat. No. 3,758,032 to Varga et al. Therein is disclosed a rail anchorage arrangement in which there is a baseplate secured to a foundation. A threaded boss or ferule is fitted to this baseplate by welding or is a press fit therein. A bolt passed through an aperture in a rail clip and threaded into the boss or ferule secures the rail clip to the baseplate. The rail clip has heel lugs symmetrically spaced about its bolt-receiving aperture. These lugs are received in recesses in the baseplate. It is these lugs in co-operation with the recesses in which they are received which provide lateral stability and the boss or ferule plays no part in this. Accordingly, the boss or ferule is thin walled whereas according to standard engineering design a nut (which the part of the boss or ferule above the baseplate effectively is) has to be at least 30% larger in diameter than the diameter of the bolt it receives to withstand tensile or lateral loading equivalent to the strength of the bolt.
The purpose of the invention is to provide an efficient and economical means of providing a body of weldable material that is a fastening device to locate a rail anchorage using a standard screw-threaded high strength bar or bolt. Since it is difficult to weld a high strength bar without destroying its strength characteristics, the invention provides a means whereby such a bar can be efficiently attached to a weld which can match the strength of the high strength bar. The invention also provides an increased amount of weld area which is advantageous when construction site welding is not of a reliable standard, enabling a standard strength screw-threaded bar to be used efficiently.
It is possible to protect screw threads of the body of weldable material of the invention that receive the screw-threaded bar or bolt beneath the rail anchorage so that the body can be re-used if re-installation is required after several years.